Car entertainment control system

Abstract

A method of pairing a smartphone to a head unit in a motor vehicle includes determining whether the smartphone is in motion by use of an accelerometer within the smartphone. A first signal is transmitted from the head unit to the smartphone. A first RSSI is received from the head unit. The first RSSI is indicative of a strength of the first signal. A second signal is transmitted from the head unit to the smartphone. A second RSSI is received from the head unit. The second RSSI is indicative of a strength of the second signal. Pairing between the smartphone and the head unit is initiated only if it was determined that the smartphone is in motion, the second RSSI is greater than the first RSSI, and the second RSSI is greater than a threshold value.

What is claimed is: 
     
         1 . A method of pairing a smartphone to a head unit in a motor vehicle, the method comprising:
 determining whether the smartphone is in motion by use of an accelerometer within the smartphone;   transmitting a first signal from the head unit to the smartphone;   receiving a first RSSI from the head unit, the first RSSI being indicative of a strength of the first signal;   transmitting a second signal from the head unit to the smart phone;   receiving a second RSSI from the head unit, the second RSSI being indicative of a strength of the second signal; and   initiating pairing between the smartphone and the head unit only if:
 it was determined that the smartphone is in motion; 
 the second RSSI is greater than the first RSSI; and 
 the second RSSI is greater than a threshold value. 
   
     
     
         2 . The method of  claim 1  wherein the second RSSI is received after the first RSSI is received. 
     
     
         3 . The method of  claim 1  wherein the pairing is initiated between the smartphone and the head unit only if it was determined by use of the accelerometer that the smartphone is in motion. 
     
     
         4 . The method of  claim 1  wherein the threshold value is indicative of the smartphone being within one meter of the head unit. 
     
     
         5 . The method of  claim 1  comprising the further step of completing the pairing via a personal area network. 
     
     
         6 . The method of  claim 1  wherein communication between the smartphone and the head unit before pairing is carried by Bluetooth LE, and is carried by Bluetooth classic during pairing. 
     
     
         7 . The method of  claim 1  wherein the first RSSI is in a first advertising packet, and the second RSSI is in a second advertising packet. 
     
     
         8 . The method of  claim 1  wherein the first RSSI is an average of a plurality of RSSI values recorded over a first period of time, and the second RSSI is an average of a plurality of RSSI values recorded over a second period of time. 
     
     
         9 . A method of pairing a smartphone to a head unit in a motor vehicle, the method comprising:
 determining whether the smartphone is in motion by use of an accelerometer within the smartphone;   receiving a first RSSI from the head unit, the first RSSI being indicative of a strength of a first signal, the receiving of the first RSSI being dependent upon the determining step;   receiving a second RSSI from the head unit, the second RSSI being indicative of a strength of a second signal; and   initiating pairing between the smartphone and the head unit only if:
 the second RSSI is greater than the first RSSI; and 
 the second RSSI is greater than a threshold value. 
   
     
     
         10 . The method of  claim 9  wherein the first RSSI is transmitted by the head unit in response to determining that the smartphone is in motion by use of an accelerometer within the smartphone. 
     
     
         11 . The method of  claim 10  wherein the second RSSI is transmitted by the head unit a predetermined time period after the first RSSI is transmitted by the head unit. 
     
     
         12 . The method of  claim 9  wherein the determining step includes low pass filtering an output of the accelerometer. 
     
     
         13 . The method of  claim 9  wherein the threshold value is indicative of the smartphone being within 30 centimeters of the head unit. 
     
     
         14 . A method of pairing a head unit to a smartphone in a motor vehicle, the method comprising:
 receiving at the smartphone a first signal from the head unit;   transmitting from the head unit a first RSSI indicative of a strength of the first signal;   receiving at the smartphone a second signal from the head unit;   transmitting from the head unit a second RSSI indicative of a strength of the second signal; and   initiating pairing between the head unit and the smartphone only if:
 it has been determined by use of an accelerometer within the smartphone that the smartphone has been in motion between a first time at which the first RSSI was transmitted and a second time at which the second RSSI was transmitted; 
 the second RSSI is greater than the first RSSI; and 
 the second RSSI is greater than a threshold value. 
   
     
     
         15 . The method of  claim 14  wherein the second RSSI is transmitted after the first RSSI is transmitted. 
     
     
         16 . The method of  claim 14  wherein the threshold value is indicative of the smartphone being within 60 centimeters of the head unit. 
     
     
         17 . The method of  claim 14  comprising the further step of completing the pairing via a personal area network. 
     
     
         18 . The method of  claim 14  wherein communication between the smartphone and the head unit before pairing is carried by Bluetooth LE, and is carried by Bluetooth classic during pairing. 
     
     
         19 . The method of  claim 14  wherein the first RSSI is in a first advertising packet, and the second RSSI is in a second advertising packet. 
     
     
         20 . The method of  claim 14  wherein the first RSSI is an average of a plurality of RSSI values recorded over a first period of time, and the second RSSI is an average of a plurality of RSSI values recorded over a second period of time.